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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16757 results found.

  1. GRB020124(=H1896): Localization of a Long GRB by HETE
  2. Possible optical counterpart to a GRB
  3. GRB011212, Optical Observations
  4. Optical polarization observations for GRB011211
  5. GRB 011130: Optical Observations of X-ray and Radio Sources
  6. GRB 011130, Radio/X-ray Comparison
  7. GRB 011212: optical observation at Asiago
  8. GRB 011211: Evidence for an Optical Break
  9. GRB 011212: optical observation at Oslo (relayed)
  10. GRB 011211, Optical Observations
  11. GRB011212, BVRI field photometry
  12. GRB011211, BVRI field photometry
  13. Fading of the optical source associated of XRF 011211
  14. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  15. GRB011130 (XRF011130) Chandra Observations
  16. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  17. GRB 011130, K band observations
  18. GRB011130 (XRF011130) SDSS PT i-band observations
  19. XRF011130: Infrared Observations
  20. GRB 011121: J-band observations
  21. GRB 011121: NIR observations, host galaxy?
  22. GRB011121: UBRI Observations
  23. GRB 011121 J-Band Astrometry
  24. GRB 011121: Detection of Bright IR Counterpart
  25. GRB011121: possible redshift, continued decay
  26. GRB 011030: TNG K-band observation
  27. XRF011030: J and K band observations
  28. XRF011030: Chandra Observations
  29. GRB011030: Z-band observations
  30. Non-triggered burst 011030 ("GRB 011030")
  31. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  32. GRB 970828: HST Observations of the Host Galaxy
  33. GRB 000131: HST Detection of the Host Galaxy
  34. GRB 970828: HST Observations of the Host Galaxy
  35. GRB010921, optical observation
  36. GRB011019: Subaru Optical Observations
  37. GRB011030 - further refinement WFC position
  38. GRB011030: radio search
  39. GRB 010921: Possible supernova component
  40. GRB010921, optical observation at early time
  41. GRB 010921, I-band observations
  42. GRB011019, optical observations
  43. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  44. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  45. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  46. GRB010928(=H1770): Localization of a Long GRB by HETE
  47. GRB010921, negative optical observations
  48. GRB010921 field photometry
  49. GRB000926, Host Galaxy Observations
  50. GRB001109, Host Galaxy Spectroscopic Observations
  51. Probable SGR or Short Duration GRB Detected by HETE
  52. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  53. GRB 010222 - WHT BVRI images
  54. GRB 010629 Optical Observations
  55. SGR1900+14: High Fluence Burst Localized by HETE
  56. GRB010629, optical observations
  57. IPN triangulation of GRB010629
  58. GRB010629: A Burst Localized by HETE
  59. SGR1900+14: Second Burst Localized by HETE
  60. SGR1900+14: A Burst Localized by HETE
  61. SGR1806-20: A Second, Intense Burst Localized by HETE
  62. SGR1806-20: Localization by HETE
  63. HETE Fully-Automated GCN Notices
  64. GRB000301C: Late-time HST/STIS observation
  65. GRB010518: a faint BeppoSAX detection
  66. GRB000418: HST/STIS Second-epoch Observations
  67. X-ray precursors to the large flare from SGR 1900+14
  68. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  69. Millimeter observation of SGR 1900+14
  70. Chandra Observations of SGR 1900+14
  71. SGR1900+14, I-band observations
  72. GRB010412, field photometry
  73. Giant flare from SGR1900+14
  74. GRB 010326b Optical Observations
  75. GRB010412: BeppoSAX GRBM and WFC observations
  76. IPN Triangulation of GRB010412
  77. GRB010324, revised field photometry
  78. GRB 980326: Late-time HST/STIS observations
  79. GRB010324, field photometry
  80. GRB010326B, field photometry
  81. GRB010326, field photometry
  82. GRB010220, field photometry
  83. Further Optical Observations of GRB 010324
  84. GRB010222, CXO X-ray observations
  85. GRB010324, optical observations
  86. GRB010326B: Localization by HETE (2nd GRB for this date)
  87. GRB 010326 optical observations
  88. GRB010326: Refined Localization by HETE
  89. GRB010326: Localization by HETE
  90. Optical Observations of GRB 010324
  91. GRB010222, late-time optical observation
  92. Support extension to the BeppoSAX mission
  93. GRB 010222, Optical Observations
  94. GRB 010222: High-Resolution Keck Spectroscopy
  95. GRB 010222 HST/Chandra TOO
  96. GRB010222 further R-band photometry
  97. GRB 010222: Keck Spectroscopy
  98. GRB010214, field photometry
  99. GRB010222, field photometry
  100. GRB010222 further R-band photometry

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